Srimad Bhagavatam Canto 06, Chapter 02, Text 31

SB 6.2.31

atha te kva gatah siddhas
 catvaras caru-darsanah
vyamocayan niyamanam
 baddhva pasair adho bhuvah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
And where have those four liberated and very beautiful persons gone who released me from arrest and saved me from being dragged down to the hellish regions?
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
As we have learned from the descriptions in the Fifth Canto, the hellish planets are situated in the lower portions of this universe. Therefore they are called adho bhuvah. Ajamila could understand that the Yamadutas had come from that region.
Srimad Bhagavatam Canto 06, Chapter 02, Text 30
Srimad Bhagavatam Canto 06, Chapter 02, Text 32